The instant invention relates generally to automobile brake systems and more particularly to a brake system which operative for preventing unwanted rearward rolling movement of an automobile after it has stopped and a brake pedal associated with the brake system has been released.
Heretofore, it has generally been necessary for automobile operators to maintain the brake pedals of their automobiles in continuously depressed conditions after their automobiles have stopped in order to prevent unwanted rolling movement. In this regard, heretofore accidents have frequently occurred when automobiles have inadvertantly rolled backwards due to carelessness or lack of skill on the part of automobile operators. In addition, many of the heretofore available brake systems have been prone to developing loose parking brake cables and hence they have often been less than entirely effective for securing automobiles after they have stopped. Further, because most drivers of automobiles do not normally maintain high levels of braking pressure after their vehicles have stopped, stopped vehicles are often moved significantly when they are impacted by other vehicles during traffic accidents. It has been found that this has substantially increased the tendency of drivers and passengers of vehicles to sustain neck injuries during collisions with other automobiles.
Accordingly, it is an object of the present invention to provide an automobile brake system having an electronic valve between the master cylinder and the wheel cylinder thereof and preferably also having a tapered bearing assembly in the wheel cylinder in order to maintain braking pressure after the automobile has stopped. More specifically, it is an object of the instant invention to provide a brake system which includes an electronic valve between the master cylinder and the wheel cylinder for maintaining braking pressure transmitted to the wheel cylinder after pedal pressure has been released in order to prevent unwanted rolling movement of the vehicle.
Another object of the instant invention is to provide a bearing assembly in the wheel cylinder of an automobile which enables the automobile to start smoothly on a hillside.